Today separating disks for disk packages in centrifuge rotors are normally manufactured through pressure turning of plane disks to a desired tapering shape, for instance a conical shape. This method of manufacturing has the disadvantage that the manufacturing is expensive and time-consuming. Each separating disk has to be pressure turned individually in a pressure lathe. Another disadvantage of the pressure turning method is that it is difficult to produce irregular shapes such as protrusions in the pressure turned disk. A further disadvantage of the pressure turning method is the difficulty to achieve a sufficient surface smoothness without subsequent treatment of the surface. A poor surface smoothness can lead to deteriorated hygienic properties.
U.S. Pat. No. 2,028,955 discloses a disk package with conical separating disks of two kinds provided in an alternating order in such a way that every second disk is even and every second disk comprises a number of distance members in the form of substantially round projections or depressions in the disk. It does not appear how the tapering shape of the separating disk has been provided, but the projections and the depressions have been provided by means of some kind of press method. The projections and the depressions have a planar portion so that by this known technique, a large contact area is formed between the distance members and the surface of the adjacent separating disk. Furthermore, the projections and the depressions are provided in such a way that a projection is followed by a depression in a radial direction. According to U.S. Pat. No. 2,028,955 a projection also lies opposite to a depression of an adjacent disk in the disk package so that a pile of alternating projections and depressions is created through the disk package.
One problem with the solution disclosed in U.S. Pat. No. 2,028,955 is that the disk package during compression is relatively rigid since the relatively hard projections and depressions lies after each other in a radial direction in the disk package, and in addition opposite to each other. Consequently, no resilient portions of the separating disks are created, which could absorb a pretensioning force ensuring a tight abutment between the separating disks also during operation when the rotation may create forces striving to remove the disks from each other. A further disadvantage is that the distance members, and especially the depressions, may have a negative influence to the flow in the interspace in the separating disks.
SE-19563 discloses a separating disk adapted to be included in a disk package in a centrifuge rotor of a centrifugal separator. The separating disk extends around and axis of rotation and along a tapering rotary symmetric surface along the axis of rotation. The separating disk has an inner surface and an outer surface, and is manufactured of a material. The separating disk has a zigzag-like shape with first protrusions extending outwardly from the tapering rotary symmetric surface and second protrusions extending inwardly from the tapering symmetric surface. The first protrusions are displaced in relation to the second protrusions seen in a normal direction with regard to the outer surface. Wire elements are provided in order to create an interspace between adjacent separating disks in the disk package. It does not appear how the separating disk is manufactured.
DE-363851 discloses a separating disk adapted to be included in a disk package of a centrifuge rotor of a centrifugal separator. The separating disk extends around an axis of rotation and along a tapering rotary symmetric surface along the axis of rotation. The separating disk has an inner surface and an outer surface an is manufactured of a material. The separating disk is configured in such a way that it creates an interspace between the separating disk an adjacent separating disk in the disk package and comprises first protrusions extending outwardly from the tapering rotary symmetric shape and second protrusions extending inwardly from the tapering rotary symmetric shape. Each first and second protrusions defines a contact zone adapted to abut an adjacent separating disk in the disk package. The contact zone of the first protrusions are displaced in relation to the contact zones of the second protrusions seen in a normal direction with regard to the outer surface. The first and second protrusions are provided after each other in a peripheral direction of the separating disk. It does not appear how the separating disk is manufactured.
DE-349709 discloses a separating disk adapted to be included in a disk package of a centrifuge rotor of a centrifugal separator. The separating disk extends around an axis of rotation and along a tapering rotary symmetric surface along the axis of rotation. The separating disk has an inner surface and an outer surface, and is manufactured of a material. The separating disk is configured in such a way that it creates an interspace between the separating disk and an adjacent separating disk in the disk package, and comprises first protrusions extending outwardly from the tapering rotary symmetric surface and second protrusions extending inwardly from the tapering rotary symmetric surface. Each first and second protrusion defines a contact zone adapted to abut an adjacent separating disk in the disk package. The contact zones of the first protrusions and the second protrusions are provided after each other seen in a normal direction with regard to the outer surface. It does not appear how the separating disk is manufactured.
SE-2708 discloses a separating disk adapted to be included in a disk package of a centrifuge rotor of a centrifugal separator. The separating disk extends around an axis of rotation and along a tapering rotary symmetric surface along the axis of rotation. The separating disk has an inner surface and an outer surface, and is manufactured of a material. The separating disk is configured in such a way that it creates an interspace between the separating disk and an adjacent separating disk in the disk package, and comprises protrusions extending outwardly from the tapering rotary symmetric surface. Each protrusion defines a contact zone adapted to abut an adjacent separating disk in the disk package. The protrusions are provided after each other in a peripheral direction of the separating disk. It does not appear how the separating disk is manufactured.